Millimeter wave (mmW) frequencies may provide a large amount of usable spectrum for communication systems and devices. For example, the 60 Gigahertz (GHz) unlicensed spectrum may provide at least 7 GHz of unlicensed spectrum and additional spectrum may become available for licensed, lightly licensed, and/or unlicensed spectrum. To close the link budget for mmW frequencies, highly directional antennas may be used and are becoming practical and common, for example in wireless high definition (HD) devices. Additionally, there is a potential for greater spatial reuse at higher frequencies including mmW frequencies than at lower (e.g. sub-6 GHz) frequencies.
The higher gain antennas that may be used for mmW communications have an associated benefit of greater directionality that may reduce the interference seen by unintended receivers. At mmW frequencies, large carrier bandwidths may be achievable with comparatively low fractional bandwidths. This may enable single radio solutions that are capable of addressing a large amount of spectrum. Utilizing mmW frequencies may also lead to lower power consumption because of highly directional antennas and the tradeoff of bandwidth and power according to Shannon's law. The mmW frequency carriers have near optical properties and may suffer from high penetration losses, high reflection losses, and little diffraction, leading to line-of-sight dominated coverage. The mmW frequencies may also be subject to propagation challenges, including high oxygen absorption concerns in the 60 GHz band.